Using namespaces: fallback to global function/constant

(PHP 5 >= 5.3.0)

Inside a namespace, when PHP encounters a unqualified Name in a class name, function or
constant context, it resolves these with different priorities. Class names always
resolve to the current namespace name. Thus to access internal or non-namespaced
user classes, One must refer to them with their fully qualified Name as in:

Przykład #1 Accessing global classes inside a namespace

<?phpnamespace A\B\C;class Exception extends \Exception {}

$a = new Exception('hi'); // $a is an object of class A\B\C\Exception$b = new \Exception('hi'); // $b is an object of class Exception